1. Field of the Invention
The present invention relates to a circulating type food and drink transport apparatus for circulatingly transporting xe2x80x9csushixe2x80x9d and the like through an endless transport path formed along a food and drink counter to serve them to customers.
2. Description of the Related Art
In a circulating type food and drink transport apparatus used in xe2x80x9csushixe2x80x9d shops usually called a xe2x80x9ckaiten zushixe2x80x9d (a xe2x80x9csushixe2x80x9d shop using a circulating type xe2x80x9csushixe2x80x9d transport apparatus), there has been ordinarily used a crescent chain conveyer Y as shown in FIG. 14. The conveyer Y has a multiplicity of supports a which are formed in a crescent shape when viewed on a plan view and mounted on a chain b circulatingly traveling in an endless fashion so that the supports a rotate relatively with respect to the chain b.
Since an endless transport path is formed and circulated in the above-mentioned conventional crescent chain conveyer Y, a curved portion inevitably exists therein. Accordingly, adjacent supports a are coupled with the chain b with necessary gaps formed therebetween so as to rotate relatively with respect to each other to permit the respective supports a to smoothly travel at the curved portion. With this arrangement, foreign substances such as grains of rice and the like are liable to enter the gaps and adhere therein. Thus, there is a problem that a time-consuming job for removing them is necessary and further the existence of the gaps themselves is not preferable from a sanitary point of view.
To solve the above problem, the applicant devised a circulating type transport apparatus in which the surface of a transport path can be very easily cleaned and technologies for the apparatus have been disclosed in Japanese Unexamined Patent Application Publication Nos. 11-225865, 11-046959, 11-164763, and 11-313747.
FIGS. 14 and 15 schematically show a part of a transport apparatus having the above magnet type transport unit, wherein the transport unit a is composed of an endlessly traveling chain b, brackets c mounted thereon at predetermined intervals, and permanent magnets d fixed on the upper surfaces of the respective brackets c.
xe2x80x9cSushixe2x80x9d plates g, each of which is received by and supported on a transport path e on both the sides of the lower surface of the outer periphery of the transport path e, are circulated by being held by the attracting force of the permanent magnets d in such a manner that the magnetic metal pieces h, which are mounted on the lower surfaces of the xe2x80x9csushixe2x80x9d plates g, approach the upper ends of the respective permanent magnets d.
In this case, the permanent magnets d are mounted such that all the polarities thereof are arranged as N-poles on a lower side and all the polarities thereof are arranged as S-poles on an upper side (or verse versa).
When the polarities of the permanent magnets d are arranged uniformly such that the N-poles thereof are disposed on the lower side and the S-poles thereof are disposed on the upper side as described above, since the magnetic lines of force of adjacent permanent magnets d are directed in the same direction to each other as shown in FIG. 16 (which shows a case in which the N-poles are disposed on the lower side), a magnetic flux density is increased, and thus a strong magnetic field is formed in a relatively wide range.
The above disposition of the polarities has an advantage that a force for attracting the xe2x80x9csushixe2x80x9d plates q is increased. However, since a force necessary to separate the xe2x80x9csushixe2x80x9d plates g from the permanent magnets d also is increased, xe2x80x9csushixe2x80x9d and the like may be dropped by a reaction force which is caused when a customer strongly pulls up a xe2x80x9csushixe2x80x9d plate g.
Further, when the permanent magnet d strongly attracts the xe2x80x9csushixe2x80x9d plate g, a large amount of friction force is generated between the xe2x80x9csushixe2x80x9d plate g and the transport path on which the xe2x80x9csushixe2x80x9d plate g slides. Accordingly, a line-shaped scratch, which represents the locus of the xe2x80x9csushixe2x80x9d plate g, is made on a transport path surface e, whereby the outside appearance of the transport path surface e is marred as well as it is made more difficult by the scratch for the xe2x80x9csushixe2x80x9d plate g to slide.
An object of the present invention, which was made to solve the above problem, is to provide a circulating type food and drink transport apparatus which can reliably transport a xe2x80x9csushixe2x80x9d plate and permits the xe2x80x9csushixe2x80x9d plate and the like to be taken up with a relatively small force and the transport path of which is not scratched.
To achieve the above object, a circulating type food and drink transport apparatus for transporting food and drink transport bodies placed on an endless transport path making use of the magnetic force of magnets disposed below a transport path includes a first magnet disposed relative to each food and drink transport body, and a multiplicity of second magnets disposed below the transport path at predetermined intervals so as to circulatingly travel, wherein the first magnet and the second magnets are disposed so that the same magnetic poles thereof confront each other.
According to the present invention, when the food and drink transport body is placed on the transport path, the first magnet confronts the second magnets with the same magnetic poles thereof facing each other. Thus, the first magnet is subjected to the repulsive force of the second magnets so as to be stably located between one of the second magnets and another second magnet adjacent to it.
When the second magnets are circulatingly traveled in a predetermined direction, the first magnet circulatingly travels at the same speed as the traveling speed of the second magnets because it tends to secure the above stable position. Since repulsive force exists between the second magnets and the first magnet, the food and drink vessel can be taken up with a relatively small amount of force as well as it is made difficult for the transport path to be scratched by the food and drink vessel when it is circulatingly transported.
In the above transport apparatus, it is preferable that food and drink vessels be locked on transport trays placed on the endless transport path and that the first magnet be disposed in/on the bottom plate of each transport tray or in the proximity of the bottom plate.
With this arrangement, neither a magnet nor a magnetic member need be mounted in/on the food and drink vessel. Thus, not only the cost of the food and drink vessel can be reduced but also when the food and drink vessel is taken up, a customer does not feel abnormally because there is no effect of magnet.
In the above transport apparatus, it is preferable that food and drink vessels be placed in/on the endless transport path and that the first magnet be disposed in/on the bottom plate of each food and drink vessel or in the proximity of the bottom plate.
With this arrangement, since only the food and drink vessels are transported, a plurality of the food and drink vessels can be placed on the endless transport path.
In the above transport apparatus it is preferable that at least two pieces of the first magnets be disposed in/on the bottom plate of each food and drink vessel or each transport tray leaving at least a predetermined space therebetween.
With this arrangement, when the food and drink vessels and the transport paths are jammed, since each second magnet passes between at least the first two magnets, the food and drink vessels and the transport tray can be prevented from floating up.
In the above transport apparatus, it is preferable that two magnets having approximately the same magnetic force be disposed leaving at least a predetermined space therebetween as the first magnets.
With this arrangement, since each second magnet passes through the center between at least the first two magnets in the occurrence of jam, the floating up of the food and drink vessels and the transport tray can be prevented as far as possible as well as the food and drink vessels and the transport trays are transported in a predetermined direction at all times by the repulsion between the first magnets and the second magnet.
In the above transport apparatus, it is preferable that a third magnet be disposed in addition to at least the two magnets as the first magnets such that the different polarities of the third magnet and the second magnets confront each other and that the third magnet is located so as to have the same distance to each of the first magnets.
With this arrangement, since the second magnets additionally attract the third magnet, the food and drink transport bodies are transported in a predetermined direction at all times.
In the above transport apparatus, it is preferable that the third magnet have magnetic force set smaller than that of at least the first magnets
With this arrangement, since the attracting force between the second magnets and the third magnet is set to a minimum value necessary to determine the transport direction of the food and drink transport bodies, the attracting force does not adversely affect the food and drink transport bodies when they are taken up.
In the above transport apparatus, it is preferable that a magnetic material which is not a permanent magnet be disposed in addition to at least the two magnets as the first magnets and that the magnetic material is located so as to have the same distance to each of the first magnets.
With this arrangement, magnetic force for determining a direction of the food and drink vessels can be obtained at a relatively low cost.
In the above transport apparatus, it is preferable that all of the second magnets have approximately the same magnetic force and that each food and drink transport body having the first magnet travel on the transport path at approximately the center between two adjacent magnets of the second magnets.
With this arrangement, since each of the food and drink vessels is located on the transport path at approximately the center between adjacent second magnets and move while keeping this position, the food and drink vessels are circulatingly transported orderly at equal intervals.
In the above transport apparatus, it is preferable that a pair of slide members having a small coefficient of friction are disposed on both the sides of the transport path so as to form a necessary gap between the first magnet of each food and drink vessel or each transport tray and the second magnets.
With this arrangement, since each of the food and drink vessels and the transport trays is transported while the bottom surfaces thereof are in sliding contact with the pair of slide members disposed on the inner bottom surfaces of the transport path and having the small coefficient of friction, they have a small slide resistance. Accordingly, when the slide members are applied to the transportation of, for example, xe2x80x9csushixe2x80x9d plates and the like, they can be circulatingly transported smoothly without the need of increasing the magnetic force of both the magnets.
It is preferable that the upper surface of each slide member have an arc-shaped cross section.
With this arrangement, since the areas of the pair of slide members in contact with the food and drink vessels or the transport trays are reduced, a frictional resistance is reduced and the food and drink vessels or the transport trays can be more smoothly transported.
It is preferable that the slide members be composed of any of fluorine resin, acetal resin, polyamide resin, polyethylene resin.
With this arrangement, since any of the above materials has a small coefficient of friction and is hard and excellent in wear resistance, the wear of the slide members is suppressed and the life thereof can be greatly increased.
It is preferable that the portion, which is in sliding contact with at least the slide members, of each food and drink vessel or each transport tray is composed of a material having a small coefficient of friction.
With this arrangement, since the slide resistance of the food and drink vessels or the transport trays are more reduced, the food and drink vessels can be more smoothly transported even if both the magnets have a small amount of attracting force.